~ A blog about IQ, the brain & success

Tag Archives: Reaction time

Reaction time is perhaps the most physiological, culture fair measure of intelligence. If your reaction time is slow, it means your brain is probably slow, and you’re deficient in a major component of intelligence. Of course reaction time is only moderately g loaded, so don’t be too depressed if you take this test and find out your reaction time is way slower than you thought. The great thing about this test is that it averages your 5 scores for you. Maybe practice for about five minutes to make sure you’re used to the test and know how it works, and then once you feel comfortable, do an official five trials and consider the average the computer calculates, your official average reaction time.

Recently self-proclaimed BGI study participant and outspoken HBD critic “Duke of Leinster” claimed on this blog that World Heavyweight Boxing Champion Joe Louis, was considered mentally slow by his friends. The Duke felt this was another example of intelligence evaluation being wrong, since the Duke felt Louis had a big head and because the Duke felt that a mentally slow person could never be the greatest boxer. I looked at the wikipedia page on Louis and couldn’t find much about his intelligence, other than the fact that he had a speech impediment and spoke very little before about age six.

However this is the third World Heavyweight Boxing champion I’ve heard of being mentally slow. The first was Muhammad Ali who according to the book A Question of Intelligence by Daniel Seligman scored an IQ equivalent of 78 on his armed services exam. The second was Mike Tyson whose school file classified him as borderline “mentally retarded” which typically means an IQ in the 70-79 range.

What are the odds that three of the world’s heavy weight boxing champions had allegedly such low IQ’s? That can’t be a coincidence. It implies a NEGATIVE correlation between IQ and boxing skill, meaning low IQ people are actually better boxers than high IQ people. But that makes no sense. Intelligence can be defined as the mental ability to adapt whatever situation you’re in to your advantage and few situations require as much real time quick thinking and mental adaptability as physical combat. Obviously we shouldn’t expect a high correlation between IQ and boxing ability because it’s primary a physical ability, not a mental one, and it’s a skill developed through much practice, but we also shouldn’t expect a NEGATIVE correlation between IQ and boxing ability.

So how do we make sense of all these allegedly low IQ boxing champions? For starters an IQ of 78 is actually kind of high when you consider that these boxers were recruited from the poorest, most culturally deprived communities in America. Although scholar Arthur Jensen became famous for claiming that IQ is highly genetic, even he admits that there’s an almost invisible segment of America that lives in environments so bad, that environment actually does matter a lot for this small population. Jensen studied culturally deprived children in the rural South and found that while they started with a respectable IQ of 85, their IQ’s slowly regressed to 70 by adolescence. Something in the environment was dragging their IQ’s down. The obvious suspect was poor schooling, but since even non-verbal IQ showed this massive decline, it may have been a decline in real intelligence, not academic skills only. In a previous post I discussed a groundbreaking theory that reaction time training improves the dynamic component of intelligence, so perhaps the culturally deprived see their IQ’s drop because they lack video games, television, and fast driving parents who take them on chronometrically stimuating road trips on freeways.

So boxers are recruited from cultures so deprived they average IQ 70, but since heavyweight boxing requires a lot of muscle and a violent personality (you must assault people for a living), and since both weight/height ratio and violence are related to low IQ, those who are recruited to box are even lower than 70; perhaps IQ 60, on average. So when you consider that boxers are recruited from the most culturally deprived, muscular, and violent segment of society, IQ is actually a huge advantage in boxing, because IQ 78 is probably much higher than the average for culturally deprived muscular violent people.

However even though IQ 78 is relatively high, it seems low for Muhammad Ali. Scholar Charles Murray felt the score was believable, but many others beg to differ, for example, scholar Tony Buzan ranks Ali as the 32nd greatest Genius of all time! I wouldn’t go that far, but Ali’s IQ of 78 was likely spuriously lowered by the fact that he was dyslexic (and opposed to joining the army) and Tyson’s IQ was likely spuriously lowered by the fact that he couldn’t read.

I also think that once these men started boxing, their IQ’s may have increased because complex reaction time has been hypothesized to improve the dynamic component of intelligence, though I don’t know if this is true or not.

Jensen reportedly claimed that Ali had an average reaction time, however scholar Leon Kamin claimed Jensen was wrong, and that Ali’s reaction speed actually approached the physiological limit of the human species!

There are a lot of problems with how we measure intelligence. Some people measure intelligence using childhood ratio scores (if a 10 year old is as smart as a 12 year old, he gets an IQ of 120, since he’s functioning at 120% of his chronological age). Other people measure IQ with deviation scores, so if a 10 year old is smarter than 90% of 10 year olds, he’s assigned an IQ of 120. Some tests define the population standard deviation at 15, others 16, others 22 or 24.

About the only thing all IQ tests agree on is that the average score is 100. But the average 20 year old is far smarter than the average 3 year old, so assigning them both an IQ of 100 gets confusing. We must clarify that 100 is the average IQ for one’s age. But IQ’s vary enormously from country to country. So an IQ of 100 is said to represent the average in America, or is it Britain? It depends who you ask. And what happens as demographic shifts cause the populations of both countries to change? What long-term consistency is there in defining IQ 100 as the American average. And what about the Flynn Effect? Average IQ has gone up by some 30 points since the Victorian era yet the average IQ is still 100? And what about dysgenics? Average IQ has gone down by 15 points since the Victorian era yet the average is still 100? I get a headache just keeping it all straight.

And is an IQ of 100 really twice as smart as an IQ of 50? Is a 10 point difference between an IQ of 120 and 130 the same as a 10 point difference between IQ 80 and 70?

Clearly, a much simpler scale is needed:

Around the turn of the millennium, a member of the unbelievably brilliant Prometheus society published one of the most interesting and important articles in the history of psychology, and amazingly, virtually no one has ever read it. The article asserted that problem solving speed doubles every 10 IQ points. The Promethean would later go on to revise the figure to every 5 points. Yes, reaction time (information processing speed) has a beautifully Gaussian distribution, but because the human mind operates in parallel, an IQ 105 is not 5% smarter than an IQ of 100, but rather twice as smart! And an IQ of 110 is four times smarter! Although the Promethean never put it in those terms, this inference was based upon the fact that no matter how cognitively homogeneous a classroom, the difference in learning speed is always at least an order of magnitude. Think back to your high school math class. The brightest kid in the class grasped what the teacher was talking about in seconds, while the dullest may take all year.

So I propose a new intelligence scale to reflect these huge differences. We could call the units of the scale BP scores (Brain Power scores) to differentiate them from IQ scores. We must first anchor our scale to some clear definable unambiguous stable level. I say, the intelligence of the average adult ape in its peak years. To the best I can determine, the average ape has a deviation IQ of 40 (sigma 15). So let’s arbitrary assign the average adult ape (IQ 40) a BP score of 1, and then double the BP for every 5 points above 40.

So the average American (IQ 100) would have a BP of about 4000, meaning they’re 4000 times smarter than an ape. The average Ivy league graduate (IQ 130) would have a BP of about 262,000, meaning they’re 262,000 times smarter than an ape. And the average academic Nobel Prize winner (IQ 150) would have a BP of 4 million, meaning they’re 4 million times smarter than an ape. And if intelligence gaps really are as huge as this scale implies, then no wonder we have so much economic inequality!

Psychologists have long noted that intelligence, along with its biological correlates like brain size and processing speed, increases with age from infancy to childhood to adolescence, before plateauing in incipient adulthood (about age 16). Thus historically, if a young adult had the reading skills of a 9-year-old, he was said to have an IQ of 56, because his mental age was only 56% as advanced as his chronological age (16+). In other words, adults with IQ 56 were thought to be as smart as 9-year-olds.

However an intelligence expert astutely caught the error in this logic. A 9-year-old only had 9 years to acquire those reading skills, while the IQ 56 adult had 16+ years. So an average 9 year old is actually smarter than an IQ 56 adult. Instead the expert suggested that more direct measures of intelligence, like reaction time, would be a better basis of comparison than acquired skills.

In a previous post I noted that modern adults (age 16 to 25), in Western countries, have simple reaction times of about 273 milliseconds and that the standard deviation for simple reaction time is thought to be 160.4 milliseconds. Now I’ve read that in this study (which I can’t access), it’s reported that the average British 9-year-old has a simple reaction time of 371 milliseconds. Now assuming that’s true, and assuming the sample is representative and, reaction time measured the same way, then the average nine-year-old is 0.61 standard deviations slower than an adult.

However because reaction time is a very crude measure of general intelligence, it can greatly underestimate the intelligence difference between groups of people, so despite some earlier objections on my part, experts would probably consider it reasonable to divided this 0.61 SD difference by 0.54 which increases it to 1.13 SD.. In other words, using simple reaction time to estimate intelligence, 9-year-olds are as smart as an adult with an IQ of 83.

So just as reaction time studies estimate modern people are about 1 SD dumber than the Victorians, by the same measure, nine years olds are about 1 SD dumber than adults. In other words, according to reaction time, the average adult today is about as dumb as a Victorian 9-year-old.

How can this be? Well, perhaps reaction time studies overestimate the intelligence of 9-year-olds and Victorians because both groups are much shorter than modern adults and thus the nerve impulses have less distance to travel. Or maybe 9-year-olds are much less developed in other properties of the brain, so reaction time overestimates their intelligence.

But even if dysgenics and mutation load has driven our general intelligence to become as low as a Victorian 9-year-old’s, better nutrition has greatly improved brain size by as much as 1.63 SD (and perhaps other properties of the brain too) and this may be creating huge gains in non-verbal intelligence. Ironically, genetic brain size has probably declined by over 0.4 SD.

Remember, general intelligence is only one part of intelligence. The nutrition driven improvements in non-verbal IQ may be greatly enhancing our technological skills, but the rest of our intelligence has declined, as we see in our dumbed down media, devoid of critical thinking skills, and the horrific vitriolic comments littering most internet news stories.

It may be hard to believe that we’ve become so genetically dumb, but as the brilliant philosopher Christopher Langan once said, the stupid don’t know that they’re stupid. And therein lies their stupidity. It also explains why so few people read this blog. I’m just too intelligent for the modern mind. 🙂

One of the most defining life changing moments of my life came in high school, when I under-performed on a grade 11 chemistry test. Suffering from sour grapes, I ranted about the chemistry test being a poor measure of intelligence. My chemistry teacher approached to ask “Can you tell me anything in chemistry that doesn’t require intelligence?”

“All the mindless memorizing we have to do,” I replied.

“You know when you talk about intelligence, there are so many different parts to it, ” he said wisely. “It’s memorization, it’s pattern recognition, it’s…”

“I think intelligence is just how quickly you can process information,” I said, cutting him off, emboldened by knowledge of Arthur Jensen’s reaction time studies.

“No,” he corrected me. “That’s only one part of it!….If you want a single umbrella to cover ALL of intelligence….” he said, slowly, carefully, spreading out his arms as far as they would reach to convey the utter vastness of the entity he was describing, “then it’s the ability to adapt; to take whatever situation you’re in, and turn it around to your advantage. That’s really what intelligence is”

Previously I blogged about research showing that Victorians had faster simple reaction times than modern people. Since simple reaction time partly reflects the basic physiological speed of the brain, some folks think Victorians were (genetically) smarter than people today.

In a paper documenting the 20th century decline in reaction speed, scholar Irwin W. Silverman considers the confounding role of height. Height has increased by 1.5 standard deviations over the last 150 years, and this may be producing spuriously slow reaction times because nerve impulses have further to travel in a taller body. However Silverman seems to dismiss this possibility, citing research showing taller people have faster reaction times.

However within generations, taller people tend to be genetically smarter than shorter people. This is thought to be because both height and intelligence (or at least its correlates: money, status) are socially valued, so people who have an above average amount of both, or either, tend to reproduce with one another, causing the genes for both to become associated. In addition, some of the same genes that influence height, may also influence intelligence. A related point is that short stature and low intelligence may both reflect genetic mutation load, or inbreeding depression.

So the fact that the nerve impulse has further to travel in tall people may be completely negated by the fact that tall people have genetically faster brains. In other words, tall people may be so mentally quick, that they still perform well on reaction time tasks despite the test being physically biased against them.

However this genetic relationship between height and intelligence probably only holds within generations. Between generations, heights differ for nutritional reasons, probably not genetic reasons, so tall modern people do not have a genetic advantage over short Victorians with which to negate the fact that the reaction time tests are physically biased against the tall.

The confounding role of height may also explain why studies investigating the relationship between intelligence and nerve conduction velocity have yielded extremely inconsistent results. Speaking of which, has anyone investigated long-term changes in nerve conduction velocity? Measures of human NCV have been collected since the 19th century, though old studies may be crude.

Now to further confuse the issue, even though the Victorian sample from which scientist Francis Galton collected his reaction time data was short by modern standards, they were actually tall by 19th century standards. This is significant because attempts have been made to correct for the elite nature of Galton’s samples by adjusting the sample for occupational status. However even when you look at the subsets of Galton’s sample who were not elite (i.e. unskilled men, aged 26+) you find they were 66.47 inches tall (see table 10 in this HBD Chick blog post), even though the average 19th century man was, according to one major study, 166 cm (65.35 inches).

So why were even the non-elite men in Galton’s sample about 0.43 SD taller than the British average? Perhaps, because as HBD Chick explained, Galton’s sample was not just elite, they were extremely self-selected, and that may have biased the sample independently of occupational status. They had to come to Galton (he didn’t come to them). These were people who were intellectually curious and literate enough to even read about Galton’s research, and motivated enough to travel (perhaps in some cases from great distances) to the museum, find Galton’s test and pay good money to take it. And why would one want to take the test so badly unless deep down, one had reason to believe in one’s own biological superiority? Is it really surprising that people who wanted so badly to demonstrate that they’re superior, actually were, and that they would be high, not just on intelligence, but on its weak genetic correlates: height and reaction time. So, if even adjusting for occupation, Galton’s sample was 0.43 SD taller than other Victorians, then perhaps they were also 0.43 SD mentally faster than other Victorians of the same occupation, skewing Galton’s data.

But above I argued that Galton’s sample did better than modern people because they’re shorter than us, but now I’m arguing they did better than other Victorians because they were taller than them. Sounds like ad hoc gibberish, and maybe it is. But remember, within generations, good genes make people both taller and mentally quicker so tall people have faster reaction times than short people. But between generations, nutrition improves height but does not appear to improve reaction time, so shorter generations should have an unfair advantage on reaction time tests because the nerve impulse has less distance to travel.

There’s been much discussion about a paper by scholars Michael A. Woodley, Jan te Nijenhuis, and Raegan Murphy, published in the prestigious journal Intelligence, arguing that genetic IQ in Western populations has declined by about 1 standard deviation since the 19th century. Although conventional IQ tests indicate people are getting smarter, the paper argues that simple reaction time (measured in milliseconds) is better for comparing people across centuries because although it’s a very crude measure of intelligence, it’s much less sensitive to the non-genetic factors that have caused the Flynn Effect.

A blogger named HBD Chick argued the paper went wrong by using poor sampling. The oldest study the paper cites was conducted by Francis Galton circa 1889. The paper was criticized for using this study because the sample is too elite to represent Victorians (only 4% of the sample was unskilled laborers, even though 75% of Victorians were). But if the vast majority of Victorians were unskilled laborers, then I suggest we use the mean reaction time of just this occupation to represent Victorians. Yes, excluding the top 25% of occupations might bias the estimate downward, but the fact that these were unskilled workers intellectually curious enough to volunteer for Galton’s study would bias the estimate upward, so it cancels out.

An analysis of Galton’s sample (see figure 10 & 11) shows that unskilled laborers aged 14-25 averaged reaction times of 195 milliseconds in males and 190 in females (an average of 192.5).

Do we have a modern sample of similarly aged people that are equally representative of a Western population? Yes. A 1993 study by W.K. Anger and colleagues (see table 2) found that a sample of American postal, hospital, and insurance workers, aged 16-25 (in three different cities) had reaction times of 260 in males and 285 in females (an average of 273). Just as unskilled labor was an average job in the 19th century, working for the post office, hospital or insurance company seems pretty average in modern times. Thus, by subtracting 192.5 from 273, we can estimate the average Western reaction time has slowed by 80.5 milliseconds since the 19th century. Since the standard deviation for reaction time is estimated to be 160.4 milliseconds (see section 3.2), reaction time has slowed by 0.50 standard deviations in over a century (equivalent to a drop of about 8 IQ points). This is actually virtually identical to the effect size the paper found using far more data points, but then they statistically adjusted the effect size, making it implausibly large. So in my humble opinion, the problem with the paper was not the samples they cited, but the statistical corrections they made.

The paper argued that since simple reaction time has a true correlation of NEGATIVE 0.54 with general intelligence, they needed to divided the effect size by 0.54 to estimate the true decline in general intelligence. The logic was that since reaction time is a very rough measure of intelligence, it underestimates the true decline in genetic intelligence. I disagree. Such inferences only make sense if you know a priori that there’s been direct selection for lower intelligence, thus dragging reaction time along for the ride, but that’s an assumption the paper was supposed to test, not rest upon. It could be the opposite. There’s been selection for slower reaction time, thus dragging intelligence along for the ride, in which case the effect size should be multiplied by 0.54, not divided. Most likely, there’s just been recent selection for more primitive traits in general, and both reaction time and genetic intelligence reflect this dysgenic effect to parallel degrees, so the change in one equals the change in the other.

To illustrate the point further, consider that height has increased by 1.5 SD since the 19th century. Height correlates only 0.2 with IQ. Would it make sense to argue that since height is such a weak proxy for intelligence, we need to divide the 1.5 SD increase by 0.2 to estimate how intelligence has changed since the 19th century? By such logic, intelligence would have increased by 7.5 standard deviations since the 19th century (equivalent to 113 IQ points)!

So clearly, the paper was unjustified in dividing the effect size by 0.54.

Without, the adjustment, Victorians were genetically 8 points smarter than moderns, which sounds a lot more believable than 14 points.

But if Victorians had a genetic IQ of 108 (by modern standards) , how could they score only 70 on the Raven IQ test? In a previous post I argued that the Raven is a culture fair IQ test and thus the low Victorian scores must be biological (Richard Lynn’s nutrition theory). Citing Richard Lynn, I also argued that malnutrition stunts non-verbal IQ (the Raven) more than Verbal-numerical IQ (I estimate by a factor of 31). So if sub-optimum nutrition stunted their non-verbal IQ by 38 points, their verbal-numerical IQ’s would have been stunted by only 38/31= 1 point. Thus the Victorians had a verbal-numerical IQ of 107, however because verbal tests are so culturally biased, their verbal scores would be artificially depressed by lack of schooling and exposure to mass media. But on a culture reduced measure of verbal-numerical ability like Backwards Digit Span, they might have scored the equivalent of 107.

So with a culture fair verbal-numerical IQ (Backwards Digit Span) of 107, and a culture fair non-verbal IQ (the Raven) of 70, their overall IQ’s would have been 86, which is 1.5 standard deviations below their genetic IQ of 108. That 1.5 SD gap between phenotype and genotype is perfectly explained by Richard Lynn’s nutrition theory, since average height in Western countries was also 1.5 standard deviations lower in the 19th century. And the great accomplishments of Victorians can be explained by their verbal-numerical IQ of 107.